Expanding core shaft



g- 1963 c. H. LORENZ ETAL EXPANDING CORE SHAFT Filed April 11, 1960 a 60m 5 .M d m B mu m N I. N R LR /U PL W W FT 8 0M 1 Mm 0k .dn 0w mm 0N#9. a a B W 3 f v f MWMH K I ,7. Q I L s mc mm R. ow mm United StatesPatent 3,101,914 EXPANDING CORE SHAFT Clermont H. Lorenz,lialdwinsville, and William R. Penrod, Oswego, N.Y., assignors to TheBlaclr-Clawson Company, Hamilton, Ohio, a corporation of Ohio Filed Apr.11, 1960, Ser. No. 21,523 1 Claim. (Cl. 242--72) This invention pertainsto expanding shafts and more particularly to an expanding shaft forsupporting a hol low core on a winder or unwinder for web material.

An expanding shaft for removably supporting a hollow core should havepositively operating core gripping elements to provide for ease in theassembly of the core and for a firm grip on the inside surface of thecore once the core is assembled over the shaft. Such a shaft isparticularly useful, for example, in the paper making industry where acontinuous web of paper is to be wound onto or unwound from a coresuitably mounted on a winder shaft. This invention provides an expandingcore shaft including one or more driven piston elements arranged forradial extending movement to effect positive engagement with a removablecore.

An advantage of this invention resides in an ability to provide accuratecentering of one or more hollow cores on a shaft which is important inachieving proper balance in high speed winding and unwinding operations.In a preferred embodiment, the shaft is arranged with a totally enclosedhydraulic system including a driving piston movable therein foreffecting the desired locking of a core through the movement of thedriven piston elements. The use of hydraulic fluid for the operation ofthe driven piston elements provides for positive and uniform forceapplication to the core as well as positive retraction out of engagementwith the core. The invention may be incorporated in .stub shafts ormandrels for thesupport of one end of a core, or a single shaft may beused to support one or more cores in true axial alignment to themandrel.

It is therefore a principal object of this invention to provide anexpanding shaft as outlined above having positive core gripping elementsfor the releasable support of a core thereon.

A further object of this invention is to provide an expanding shaft asoutlined above having a mechanism which effects substantially uniformforce engagement with an inside surface of a core to hold the core on amandrel against slippage.

A still further object of this invention is to provide an expandingshaft as outlined above arranged to hold a removable, core concentricwith the center line of the mandrel.

Another object of this invention is to provide an expanding shaft asoutlined above including an enclosed hydraulic force transmission systemfor effecting engagement with, and disengagement from, a hollow core.

Other objects and advantages of the invention will be apparent from thefollowing description, the accompanying drawing and the appended claims.

in the drawing- FIG. 1 is a side view of a shaft constructed inaccordance with this invention showing a core in section positionedthereon;

:FIG. 2 is an end view of the shaft of FIG. 1;

FIG. 3 is a section taken generally along the line 3-3 of FIG. 2 throughthe end of the shaft and showing the details of the driving piston;

FIG. 4 is a cross section through the shaft taken generally along theline 4-4 of FIG. 1 showing the details of the core engaging mechanism;

FIG. 5 is a fragmentary view partly in side elevation and partly brokenaway in axial section showing a d id-lfill Patented Aug. 27, 1963 shaftconstructed in accordance with the invention wherein the several drivenpistons are connected by an axially extending bar;

FIG. 6 is a section on the line 66 of FIG. 5; and

FIG. 7 is a fragmentary elevational view looking down on FIG. 6 with thecore removed.

Referring to the drawing, which illustrates preferred embodiments ofthis invention, the body of a shaft suitable for use in a paper windingor unwinding machine is illustrated generally at It The shaft 10includes a pair of spaced apart bearing surfaces 11 and 12 and anintermediate mandrel portion 14. The shaft 10 has an extended end 15upon which is formed a connection 16 by means of which the shaft may beoperatively connected with a clutch brake, or any drive or holdingconnection, as desired. The bearing surfaces or land areas 11 and 12 arearranged to work with suitably removable bearings (not shown) for theready removal and mounting on a winding or unwinding machine.

The mandrel portion 14 of the shaft 10 is adapted to receive a hollowcore 20 thereon. The core 20 may be formed of paper, plastic, steeltubing, or any other material as desired, according to its intended use.The dimension of the mandrel portion 14 is such as to permit the readyinsertion of the core 20 thereover.

The shaft includes a coaxially extending bore forming a hydraulic fluidchamber 25 within the shaft 10. The chamber 25 is closed at the end 15of the shaft 10 by an integral wall 26 and is closed at the other end 27of the shaft by a threaded plug 28 having a plunger portion on its endwhich forms a driving piston 29. The plunger piston 25 forms means bywhich hydraulic tluid may be displaced from within the chamber 25, andit is arranged for reciprocal movement within a cylinder 30 formed inthe shaft. A fluid tight seal is effected between the piston 29 and thecylinder 30 by means of suitable packing, such as a single elastomericring 31 arranged in an appropriately formed groove on the piston 29. Thering 31 may, if desired, be provided with a pair of leather back-upwashers 32.

The end 27 of the shaft 10 is internally threaded as indicated at 33,and forms a means by which the axial position of the plug 28 may beadjusted to regulate the position of the piston 29 within the cylinder30. A drive nut 34 is welded to the exposed end of the plug 28 by meansof which the plug 28 may be turned either in- Wardly to displace fluidfrom within the chamber 25 or outwardly to increase the displacement ofthe chamber. Entrapped air in the chamber 25 may be removed through ableed passageway 35 in the piston by removing a plug 36 in the nut 34. Aretaining ring 37 cooperates with the shank portion 3% of the plug 28which is of reduced diameter to prevent the plug from being screwed allthe Way out of the shaft.

Means for effecting a positive gripping engagement with the inside of acore 20 upon the displacement of hydraulic fluid within the chamber 25includes a plurality of driven piston assemblies indicated at 40. Thepiston assemblies include hardened plugs 41 tapped into threadedopenings radially formed at spaced intervals along the length of themandrel and into the chamber 25. A driven piston 42 is mounted withineach of the plugs 41 for limited radial extended and retracted movementtherewithin. Suitable packing, such as an elastomeric ring 43 positionedbetween a pair of leather back-up washers 44 on each of the pistons 42,effects a fluid tight seal between the chamber 25 and the plug 41.

The pistons 42 each include a core gripping outer end 45, and anenlarged inner end portion 46 received within the chamber 25. In thefully retracted position as shown in FIG. 4, the portion 46 of thepiston 42 is bottomed d) in its inner limit position against the insidewall of the chamber 25. Means for limiting the maximum outward extendedmovement of the piston 42 in relation to the mandrel portion 14 includesa shoulder 47 on the portion 46 engageable with the bottom of the plug41 in the extended position of the piston 42. The end 45 of the piston42 is preferably spherically curved for smooth engagement with the innersurface of the core 20.

The number of the piston assemblies 40 is determined by the length ofthe mandrel portion 14 of the shaft 10 and the desired distribution ofthe clamping force effected thereby, satisfactory results being obtainedwith these assemblies spaced approximately 3 inches apart when manynarrow cores are used and 6 to 8 inches apart when longer and fewercores are used. The force on each piston 42 is a function of pressurebuild-up by piston 29. Also, the force effected by each piston 42against the inside surface of the core 20 will be equally distributed byeach of the assemblies 40 to obviate the likelihood of distortion of thecore.

Additional core support is provided by fixed core supports consisting ofa pair of angularly spaced ribs -0 and 51 extending substantially thelength of the mandrel portion 14. The ribs 50-51 are arranged forengagement with the inside surface of the core in cooperation with thepiston assemblies 40 to provide for support and gripping at peripherallyequally spaced points and preferably of such dimension as to hold thecore concentric with the mandrel portion 14. The ribs 50-51 are securedto the shaft by means of spaced countersunk screws 52.

The operation of this invention is largely evident from the precedingdescription. The shaft 10 is removed from its bearing supports and thedriving piston 29 is retracted by application of a suitable tool to thenut 34 and rotating to withdraw the plunger 29 within the cylinder 30.This has the effect of withdrawing each of the pistons 42 of theassemblies 40 into their inner retracted positions, thereby releasingany core or core multiple sections which had been mounted thereon andproviding for the insertion of a new core 20 over the mandrel portion14. The core 20 is secured in place by turning the driving piston 29, bymeans of the nut 34, into the cylinder thereby effecting a displacementof hydraulic fluid within the chamber 25. The hydraulic pressure withinthe chamber 25 will displace each of the pistons 42 outwardly with equalforce into engagement with the inner surface of the core 20 to securethe core against the exposed outer end 44 of the piston 42 and the ribs50 and 51 concentric to the center line of the shaft.

It is understood that the piston assemblies 40 may be operated remotelyfrom a remote source of fluid pressure by means of a fluid connectioninto the chamber 25 preferably at the plug 28 through a quick disconnectand pressure holding fluid connection. Such connection may be made byremoving the plug 36 and applying the piston operating fluid pressurethrough the passageway of the plug 28, if desired. Also, it isunderstood that such external source of pressure may be used tosupplement the pressure within the chamber 25 as to increase or decreasea pressure established by the piston 29. It is also within the scope ofthis invention to provide a stub shaft supported by bearings at one endonly for locking engagement with one end of a core.

.In the form of the invention shown in FIGS. 5-7, the shaft 60 isgenerally similar in construction to the shaft 10 and includes a similaraxial chamber 61 to be filled with hydraulic fluid, and one end of theshaft 60 is provided with a control piston as shown in FIG. 3 for theshaft 10. The shaft 60 is provided similarly to the shaft 10 with aplurality of tapped radial bores 62 which receive threaded annular plugs63 for supporting driven pistons 65 in the same manner as described forthe plugs 41 and pistons 42. Instead of these pistons operatingindividually, however, they are connected by an axially extending bar 66to provide a gripping action over the 4 entire length of the interiorsurface of the core 20 in combination with the keys or ribs 50 and 51.

In order to accomplish this result, the shaft 60 is provided with amilled slot '70 extending axially thereof to receive the bar 66, butthis slot does not extend all the way into the internal chamber 61. Theouter end of each of the pistons 65 is slotted as shown in FIG. 6 toreceive the bar 66, and a pin 71 forms a pivotal connection for the barin each of these slotted pistons. With this arrangement, when thepressure is applied as described in connection with FIGS. 1-4, thepistons 65 move radially outwardly and thus carry the bar 66 into thedesired gripping engagement with the inner surface of the core.

It is therefore seen that this invention provides an expanding shaftwhich is characterized by simplicity and positive action for grippingand centering a hollow core and for releasing such core at will. Itincludes a minimum of working parts and provides substantially uniformtension forces along the length of a core mounted for rotation thereon.It is preferably self-contained and includes working parts which areconstructed for minimum wear in use and therefore provide a long servicelife.

While the forms of apparatus herein described constitutes preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparatus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claim.

What is claimed is:

A self-centering expanding core shaft for removably gripping a hollowcore, comprising an elongated generally cylindrical body having adiameter less than that of said core to be received thereon and havingmeans defining a hydraulic liquid chamber therein extending through oneend thereof and terminating adjacent the opposite end of said body,means in said one end defining a driving cylinder, an operator includinga driving piston formed on the inner end thereof received in saidcylinder closing one end of said chamber and having an outer driving endthreadedly received in said body for liquid displacing movement in saidbody, a plurality of spaced apart driven piston assemblies arranged in asingle row on said body including means defining a radially extendingcylinder bore communicating with said fluid chamber, a driven piston foreach of said assemblies having a portion forming a seal with said boreand movable outwardly and inwardly in direct proportion to fluiddisplacing movement of said driving piston, the outer ends of each ofsaid driven pistons being proportioned for direct engagement with theinside surface of said core at longitudinally spaced apart positionsupon extending movement thereof, means on said body defining a pair oflongitudinally extending 'gnooves spaced substantially at intervals fromeach other and from said row of piston assemblies and a separate ribfixedly received and supported along the length of each of said grooveshaving an outer core gripping surface proportioned to engage the insidesurface of said core upon said outward movement of said driven pistonsproviding three point support for said core on said shaft.

References Cited in the file of this patent UNITED STATES PATENTS1,192,063 Hoberg July 25, 1916 1,908,562 Shaffer et al. May 9, 19332,062,421 Lindbom Dec. 1, 1936 2,204,475 Crandall June 11, 19402,215,069 Meisel Sept. 17, 1940 2,321,146 Jones June 8, 1943 2,558,689Miller June 26, 1951 2,630,278 Herman Mar. 3, 1953 (@ther references onfollowing page) 6 UNITED STATES PATENTS 1,074,746 France Apr. 7, 19542,688,218 Taylor Sept. ,7, 1954 7 3 Great i i 30, 1955 795 111 BruesfleMan 29, 1955 827,664 Great Bfiflam 1960 2,971,765 Atherhold Feb. 14,1961 5 OTHER REFERENCES FOREIGN PATENTS Germany application G-12219,printed May 24, 1956 679,925 Great Britain Sept. 24, 1952 556 0

